I'd MP product for my customer from 2013/4 to now, it's work find.
But now I'm fix some fail main board.
I find the main board can't boot.
1. Using OTG to check the power status, PC can find a new device "SE Blank ELVIS".
2. No connect OTG, and power on, the debug port no any string shown. (SD boot card is good)
3. Using scope check the SD1_CLK, it has signal shown.
4. Check SD1_CMD, no any signal shown.
Would you help to tell us what's happen ??
How about the boot (power on) steps ?
Where point we need to check it ?
We need your best help to teach us to fix some fail board.
We had check some signal between working & fail board.
Thanks a lot~